KR101425394B1 - Power Converting System with Diagnostic or Regeneration Function for Battery - Google Patents

Abstract

A power conversion system having a battery diagnosis or regenerative function according to a preferred embodiment of the present invention includes a power converter for converting an input AC power into a DC power; A battery management device for managing charging or discharging of N batteries; And a controller for controlling the battery manager. The battery management unit may further include: an individual managing unit for managing each of the N batteries; And an aggregate management unit for managing the N accumulators as a set.
According to the power conversion system having the battery diagnosis or regenerative function of the preferred embodiment of the present invention, the life of the battery can be extended by diagnosing and regenerating chemical deterioration, which directly and significantly affects the life of the battery.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power conversion system having a battery diagnosis function or a regenerative function,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion system having a battery diagnosis or regeneration function, and more particularly, to a power conversion system capable of diagnosing or regenerating a battery in which an electrode is oxidized and an impedance component inside the battery becomes large, .

The deterioration of a battery used in a power conversion system for supplying power of a system and / or a battery to a load can be largely divided into physical deterioration and chemical deterioration. Physical deterioration refers to a phenomenon in which erosion of the electrode plate is increased due to long-term charge / discharge, use in a high temperature environment, expansion / contraction is repeated, and eventually the electrode plate is peeled off, Further, the chemical deterioration means that sulfate ion crystals having poor conductivity are generated in the electrode plate by repetition of charging and discharging, and as a result, the active plate surface is deteriorated.

Even if the discharged battery is left unattended or the battery is not completely discharged in a fully charged state, a chemical reaction takes place inside the battery, and the capacity of the battery decreases due to self-discharge with the lapse of time. Therefore, a battery left over a long period of time is overdischarged by self-discharge, sulfation material is formed, internal impedance is increased, and the function of the battery is lost.

Generally, there is no separate diagnosis or countermeasure for the battery condition in the power conversion system that is generally used, and there is no separate countermeasure against chemical deterioration which directly and greatly affects the lifespan. Thus, the life of the battery is very shortened .

1. Korean Patent Publication No. 10-2005-0003923: Method of inspecting battery pack using impedance measurement technique 2. Patent Publication No. 10-2011-0077774: Battery pack management device and method

An object of the present invention is to solve the technical problems described above, and it is an object of the present invention to provide a battery diagnosis or diagnosis method capable of extending the service life of a battery by diagnosing and regenerating chemical deterioration, And an object thereof is to provide a power conversion system having a reproducing function.

A power conversion system having a battery diagnosis or regenerative function according to a preferred embodiment of the present invention includes a power converter for converting an input AC power into a DC power; A battery management device for managing charging or discharging of N batteries; And a controller for controlling the battery manager.

The battery management device may further include: an individual management unit for managing each of the N batteries; And an aggregate management unit for managing the N batteries as a set. Specifically, the individual management unit may include: an individual information detection unit that detects information of each of the N batteries; And an individual charging power source unit for supplying power for individually charging each of the N batteries. The aggregate management unit may further include: an aggregate information detection unit that detects information from the N battery groups; And an assembled charging power source unit for supplying power for charging the N battery assemblies.

The controller is configured to control charging of the N battery assemblies or a part thereof using one of the outputs from the set charging power source unit or the individual charging power source unit. It is preferable that the individual charging power source unit generates a pulse power source of a predetermined frequency or more.

Specifically, the battery management device is characterized in that the N accumulators are charged with the first current value until the first battery voltage reaches the first voltage value by using the output from the set charging power source unit . The controller determines whether the N battery assemblies are abnormal by calculating the time at which the first voltage value is reached. The battery management device may further include a switch unit for selecting one of the individual management units or the aggregate management units for each of the N batteries.

Preferably, the controller is configured to detect an abnormal battery among the N batteries by using the individual information detecting unit when the N battery sets are determined to be abnormal based on information from the aggregated information detecting unit do. The controller is configured to charge the battery determined as the abnormal battery using the individual charging power source unit and to charge the battery not determined as the abnormal battery using the integrated charging power source unit.

Specifically, the switch unit includes a first switch group including N switches, a second switch group including N switches, and a third switch group including N switches, wherein the N first switch groups A first switch which is one of the switches, one of the N accumulators, and a second switch which is one of the switches of the N second switch groups are connected in series in order, 3 switch is connected in parallel with the first switch, which is in turn connected in series, one of the N batteries, and the second switch.

When the N battery assemblies are determined to be abnormal by the information from the aggregated information detection unit, the first switch and the second switch connected in series to one of the N accumulators are turned off And the third switch is turned on. The controller is further configured to operate the individual information detecting unit by turning off the first switch and the second switch connected in series with one of the N accumulators and turning on the third switch. do.

Specifically, when one of the N accumulators is determined to be abnormal as a result of detecting one of the N accumulators by the individual information detecting unit, the controller sets the N To charge one of the batteries. When one of the N accumulators is determined to be normal as a result of detecting one of the N accumulators by the individual information detecting unit, the first switch and the second switch are turned on And the third switch is turned off.

According to the power conversion system having the battery diagnosis or regenerative function of the preferred embodiment of the present invention, the life of the battery can be extended by diagnosing and regenerating chemical deterioration, which directly and significantly affects the life of the battery.

1 is a characteristic curve of a typical battery.
Fig. 2 is a charge explanatory diagram by simple modeling of a capacitor. Fig.
3 is a graph showing a change in specific gravity of a terminal voltage and an electrolyte when a discharged battery is charged with a constant current.
FIG. 4 is a graph of charging voltage and charging current with time during battery charging.
5 is a flow chart of a method for determining abnormal battery life according to a preferred embodiment of the present invention.
6 is a configuration diagram of a power conversion system having a battery diagnosis or regenerative function according to a preferred embodiment of the present invention.
7 is a configuration diagram of a switch unit according to a preferred embodiment of the present invention.

Hereinafter, a power conversion system having a battery diagnosis or regenerative function according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

It should be understood that the following embodiments of the present invention are only for embodying the present invention and do not limit or limit the scope of the present invention. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

First, FIG. 1 shows a characteristic curve of a typical battery.

As can be seen from Fig. 1, when the battery is normal (t1), the impedance inside the battery maintains the reference line. However, at the end of life (t2), the impedance inside the battery suddenly changes, and when the capacity of the battery reaches 80% of the rated value, the internal impedance goes up by more than 30%.

FIG. 2 is a charge explanatory diagram by simple modeling of a capacitor. FIG. When the battery is charged using a charger, the specific gravity of the electrolyte is increased, and the terminal voltage of the battery also rises.

FIG. 3 shows a change in the specific gravity of the terminal voltage and the electrolyte when the discharged battery is charged with a constant current. The voltage rapidly rises at the beginning of charging and continues to rise slowly for a while, - 2.4V), the rate of voltage increase sharply increases, and after that, the rate of re-rise slows down, eventually reaching a constant voltage. Even if the charging continues, the charging is completed without increasing the voltage. In this case, the constant voltage should be maintained.

FIG. 4 shows a graph of charging voltage and charging current with time during charging of the battery.

As can be seen from FIG. 4, when a charge current (constant current) set arbitrarily for charging the battery is made to flow, the charge voltage Vchg of the battery becomes lower than the charge voltage Vchg at the portion where the voltage drop occurs due to the internal resistance Rs Is added and set. That is, Vchg (charge voltage) = V (terminal voltage) + I (charge current) * battery internal resistance Rs.

When the battery is normal, the internal impedance of the charger is low as shown in FIG. 1. Therefore, when charging is performed as shown in FIG. 4, the charging curve inside the battery takes a predetermined charging time to be charged. However, when the battery becomes an end-of-life and the impedance inside the battery increases, the charging curve inside the battery reaches the charging voltage sooner. That is, as can be seen from FIG. 4, when a current flows from the charger to the battery for charging, the charging voltage rises.

In the present invention, since the internal impedance of the battery is determined while charging the battery, the life of the battery is diagnosed. Therefore, the charge voltage is read and the time is calculated by integrating the charge voltage.

5 is a flowchart of a method for determining abnormality of a battery life used in a power conversion system having a battery diagnosis or regeneration function according to a preferred embodiment of the present invention.

As can be seen from FIG. 5, the method for determining whether the battery life is abnormal according to a preferred embodiment of the present invention includes charging a battery (BATT) by a set current value (S10), reaching a set voltage value (S20). If the set voltage value has been reached, it is determined whether the charging time is equal to or longer than the set time (S30). Next, if the charging time is longer than the set time, the battery BATT is determined to be normal (S40). If the charging time is shorter than the set time, the battery BATT is determined to be longer than the life time (S50).

6 is a configuration diagram of a power conversion system having a battery diagnosis or regenerating function according to an exemplary embodiment of the present invention.

6, a power conversion system having a battery diagnosis or regenerating function according to an exemplary embodiment of the present invention includes a power converter 10, an inverter 20, a controller 30, and a battery manager 40 .

First, the power converter 10 serves to convert AC power input from the system power supply to DC power. Next, the inverter 20 converts the DC staff output from the power converter 10 into AC power and supplies it to the load. That is, the inverter 20 can convert power to a clean sinusoidal power source that is independent of the input voltage by switching the power source at a high frequency having a predetermined period (for example, 15 KHz) to supply power to the load.

Further, the battery (BATT) can be charged by the constant voltage and constant current method using the output of the power converter (10).

Next, the controller 30 serves to control the battery manager 40. [

The battery management device 40 according to the preferred embodiment of the present invention plays a role of managing charge or discharge of N batteries (BATT). The battery management device (40) of the present invention includes an individual management section (41), an aggregation management section (42), and a switch section (43).

Specifically, the individual managing unit 41 serves to individually manage each of the N batteries BATT, and includes an individual information detecting unit 411 and a separate charging power source unit 412. The individual information detecting unit 411 detects information of each of the N batteries BATT, and the individual charging power source unit 412 supplies power for individually charging each of the N accumulators BATT.

The aggregate management unit 42 includes an aggregate information detection unit 421 and an aggregate charge power source unit 422. The set information detecting unit 421 detects information from the N sets of BATTs and the set charge power source unit 422 serves to supply power for charging the N sets of BATTs.

Specifically, the aggregate information detecting unit 421 according to the preferred embodiment of the present invention includes N sets of accumulators (BATTs) as one set, that is, one set of N sets of accumulators (BATT) As shown in FIG. In particular, the information detected by the aggregate information detection unit 421 may be voltage, current, and temperature, for example, and makes the detected information available to the controller 30. [

The separate information detecting unit 411 and the aggregated information detecting unit 421 are separately provided in the individual managing unit 41 and the collective managing unit 42 in the present invention to keep the individual information detecting unit 411 always in the ON state , There is a problem of power consumption because of the necessity of detecting information such as voltage, current, and temperature value from each of the N batteries (BATT), so that N sets of accumulators (BATT) (BATT) in which the individual information detecting unit 411 actually detects an abnormality after first determining whether or not there is a primary abnormality.

As a result, the power conversion system of the present invention is capable of controlling the power conversion system of the present invention by controlling one or more of N accumulators (BATT) sets or And a part thereof is charged. That is, the controller 30 operates the individual charging power source unit 412 or the assembled charging power source unit 422 using the information from the individual information detection unit 411 or the aggregated information detection unit 421 do.

The controller 30 also controls the N accumulators BATT by using the output from the set charge power source unit 422 until the first voltage value is reached by the first current value, And it is determined whether or not the set of N batteries BATT is abnormal by calculating the time at which the first voltage value is reached. Specifically, when the set of N accumulators (BATT) is judged to be abnormal by the information from the set information detecting unit 421, the controller 30 uses the individual information detecting unit 411 to detect N batteries (BATT (BATT). The controller 30 charges the battery BATT determined to be the abnormal battery BATT by using the individual charging power source unit 412 and the battery BATT that is not determined as the abnormal battery BATT, Unit 422 to be charged.

Further, in the present invention, the individual charging power source unit 412 can regenerate the battery BATT by generating a pulse power source at a frequency or higher and supplying it to the battery BATT judged as abnormal.

In addition, the switch unit 43 according to the preferred embodiment of the present invention can select one of the individual management unit 41 or the aggregate management unit 42 for each of the N batteries BATT.

7 shows a configuration diagram of a switch unit 43 according to a preferred embodiment of the present invention. 7, the switch unit 43 of the present invention includes a first switch group SW1 including N switches, a second switch group SW2 including N switches, And a third group of switches SW3. Specifically, the first switch, which is one of the first switch groups SW1, one of the N accumulators BATT, and the second switch, which is one of the second switch groups SW2, are connected in series in order, And the third switch SW3 is connected in parallel with the first switch connected in series, one of the N accumulators BATT and the second switch.

Specifically, when the controller 30 determines that the set of N batteries (BATT) is abnormal due to the information from the set information detecting unit 421, The first switch and the second switch connected in series to one of the N accumulators BATT are turned off and the third switch is turned on.

That is, the first switch and the second switch connected in series with one of the N accumulators BATT are turned off, and the third switch is turned on, whereby the individual information detecting unit 411 of the individual managing unit 41 and the individual The charging power source unit 412 and the N batteries BATT are individually connected.

When one of the N accumulators BATT is determined to be abnormal as a result of detecting one of the N accumulators BATT by the individual information detecting unit 411, Unit 412 to charge one of the N accumulators BATT.

Specifically, the controller 30 turns off the switches of the first switch group SW1 and the switches of the second switch group SW2, which are respectively connected to the first storage battery BATT1 of the N accumulators BATT, And the switch of the third switch group SW3 connected in parallel is turned on. Next, the controller 30 turns on the switches of the first switch group SW1 and the switches of the second switch group SW2, which are connected to the first accumulator BATT1 of the N accumulators, respectively, The switch of the connected third switch group SW3 is turned off and the switches of the first switch group SW1 and the switches of the second switch group SW2 connected to the second accumulator BATT2 of the N accumulators BATT up- The switch is turned off, and the switch of the third switch group SW3 connected in parallel with the switch is turned on. The controller 30 controls the switches of the first switch group SW1 and the switches of the second switch group SW2 connected to the battery BATT from the first battery BATT1 to the Nth battery BATTN, Then, by sequentially turning on / off the switches of the third switch group SW3, it is possible to determine which battery BATT1 is an abnormal battery.

Specifically, when the individual information detecting unit 411 detects one of the N accumulators BATT as a result of detection of one of the N accumulators BATT, One switch of the switch group SW1 and one switch of the second switch group SW2 are turned on and one switch of the third switch group SW3 is turned off, Lt; / RTI >

The operation of a power conversion system having a battery diagnosis or regenerative function according to a preferred embodiment of the present invention will be summarized as follows.

First, the output of the power converter 10 is supplied to the load via the inverter 20. [ Further, when an emergency such as power is not applied from the system, the output of the charged battery is supplied to the load by using the output of the power converter 10.

However, it is necessary to judge whether or not the life of the battery is abnormal and to regenerate the battery. In order to determine whether or not the life of the battery (BATT) is abnormal, the N accumulators BATT are charged to the first voltage value with the first current value using the output of the integrated charge power source unit 422, Voltage and temperature of a set of N accumulators BATT (all of the N accumulators BATT as one unit) by using the battery 421. [ The controller 30 calculates the time when the set of N batteries BATT reaches the first voltage value by using the current and the voltage of the N sets of BATT detected from the set information detecting unit 421 .

If the time when the first voltage value calculated by the controller 30 is less than the predetermined time is a state in which some of the batteries BATT included in the N sets of BATTs are abnormal, The detection unit 411 is used to detect the voltage and the current while charging each of the N accumulators BATT to the second voltage value by the second current value. Finally, the controller 30 calculates the time at which each of the N batteries BATT reaches the second voltage value based on the detected voltage and current information, and the battery BATT ) Is finally determined to be an abnormal battery (BATT).

In a power conversion system having a battery diagnosis or regenerative function according to a preferred embodiment of the present invention, a battery (BATT) determined as an abnormal battery (BATT) is charged using an individual charging power source unit 412, The battery BATT determined to be normal is charged by using the set charging power source unit 422 so that the battery BATT judged as normal other than the abnormal battery BATT is judged as to whether the abnormal battery BATT is regenerated So that it can be continuously operated irrespective of the type of the apparatus.

Further, when charging is performed using a high frequency pulse using the individual charging power source unit 412 for reducing the sulfation of the abnormal battery BATT with respect to the abnormal battery BATT, In the electrode plate, the particles that form the electrode are increased in energy level according to the pulse charge, and the process is activated repeatedly, and the sulfurized foreign substances are separated from the electrode plate. This exfoliation causes the oxidized foreign substance to fall off from the electrode plate and restore the original function of the electrode. When the internal impedance of the battery BATT returns to a normal value due to the recovery, the battery BATT is charged using the output of the power converter 10 because the battery BATT is no longer an abnormal battery BATT.

As described above, according to the power conversion system having the battery diagnosis or regenerating function according to the preferred embodiment of the present invention, the chemical degradation that directly and significantly affects the life of the battery is diagnosed and regenerated, It can be extended.

10: Power converter 20: Inverter
30: Controller 40: Battery management device
41: individual management unit 42:
43:
411: Individual information detecting unit 412: Individual charging power source unit
421: Collective information detecting unit 422: Collective charge power source unit
SW1: first switch group SW2: second switch group
SW3: Third switch group BATT: Storage battery

Claims (16)

A power converter for converting input AC power into direct current power;
A battery management device for managing charging or discharging of N batteries; And
And a controller for controlling the battery management unit,
The battery management device may further include: an individual management unit for managing each of the N batteries; And a set management unit for managing the N batteries as a set,
Wherein the individual management unit comprises: an individual information detection unit for detecting information on each of the N batteries; And an individual charging power source unit for supplying power for individually charging each of the N batteries,
Wherein the collective management unit comprises: an aggregated information detection unit for detecting information from the N battery assemblies; And an assembled charging power source unit for supplying power for charging the N battery assemblies,
Wherein the controller controls to charge the N battery assemblies or parts using one of the outputs from the set charging power source unit or the individual charging power source unit. delete delete delete delete The method according to claim 1,
The individual charging power source unit includes:
And generates a pulse power source having a frequency higher than a predetermined frequency. The method according to claim 1,
The battery management device includes:
And the N sets of battery cells are charged by the first current value until the first voltage value is reached by using the output from the set charge power source unit. 8. The method of claim 7,
The controller comprising:
And determining whether the N battery assemblies are abnormal by calculating a time when the first voltage value reaches the first voltage value. The method according to claim 1,
The controller comprising:
And detects the abnormal battery among the N batteries by using the individual information detecting unit when the N battery sets are determined to be abnormal based on the information from the set information detecting unit. Powered power conversion system. 10. The method of claim 9,
The controller comprising:
Characterized in that the battery is charged by using the individual charging power source unit and the battery which is not determined as the abnormal battery is charged by using the set charging power source unit Power conversion system. The method according to claim 1,
The battery management device includes:
And a switch unit for selecting one of the individual management units or the collective management units for each of the N batteries. 12. The method of claim 11,
Wherein,
A first switch group including N switches, a second switch group including N switches, and a third switch group including N switches,
A first switch which is one of the switches of the N first switch groups, one of the N accumulators and one of the switches of the N second switch groups are sequentially connected in series,
And the third switch, which is one of the switches of the N third switch groups, is connected in parallel with the first switch connected in series, one of the N batteries and the second switch in series. / RTI > 13. The method of claim 12,
The controller comprising:
The first switch and the second switch connected in series to one of the N accumulators turn off when the N battery assemblies are determined to be abnormal by the information from the aggregate information detecting unit, Is turned on. The power conversion system has a battery diagnosis or regeneration function. 14. The method of claim 13,
The controller comprising:
The first switch and the second switch connected in series to one of the N batteries are turned off and the third switch is turned on to operate the individual information detecting unit. Power conversion system. 15. The method of claim 14,
The controller comprising:
When one of the N accumulators is detected as a result of detecting one of the N accumulators by the individual information detecting unit, one of the N accumulators is charged using the individual charging power source unit And the power conversion system has a battery diagnosis or regeneration function. 15. The method of claim 14,
The controller comprising:
The first switch and the second switch are turned on when one of the N accumulators is determined to be normal as a result of detecting one of the N accumulators by the individual information detecting unit, Wherein the switch is turned off. ≪ Desc / Clms Page number 24 >

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